Breech operating mechanism



w. SUMMERBELL BREECH PERATING MECHANISM Jan. 27, 194s.

Filed Junge l, 1944 2 Sheets-Sheet 1 L Willinm Emmrerhell am c. f. WMMM Gum/wup Jan. 27, 1948. w. suMMr-:RBELL BREECH OPERATIG MECHANISM 2 sheets-sheet 2 Filed June l, 1944 ilu i l Willinrn ummerbell w, @MWMMM www Y Patented Jan. 27, 1948 UNITED STATES PATENT OFFICE amended April 30, 1928; 370 O. G. 757) The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment to me of any royalty thereon.

The invention relates to means formanually opening the breech closures in guns wherein a semiautomatic operation of the closure is effected, or where incomplete recoil action is involved.

The invention has for an object to enable the use of a hand lever to operate a breech closure to move it positively from closed to open position at Will, yet enabling this lever to rest stationary during normal automatic opening and normal closing operations of the closure, avoiding danger from movements of the lever such as might occur if connected to move through its full stroke in both directions on each firing operation effected by the automatic members.

While the invention is adaptable to various constructions of breech mechanism, it is in the present instance applied to mechanisms such as have been used on 75 mm. tank guns and some others of other caliber, and it is a particular aim ofthe invention to embody such a device in an extremely simple and compact form making it exceptionally important for use on the large caliber armament of tanks. In the same direction it is sought to simplify and make more positive and certain the functioning of the lever latch in such a device.

It is a special purpose to enable the quick and certain manipulation of the latch and lever in the hasty action often involved under combat encounters, and particularly to avoid requiring an exact position of the hand on the lever grip when releasing the lever latch, as well as to avoid requirement of preliminary motion of the lever incident to release of the latch.

A further aim of the invention is to present a construction which may be produced with a minimum complication in production, requiring a minimum amount of material, and enabling the use of standard production details heretofore used as a major portion of the mechanism required.

It is a, feature of value that the lever may be operated with facility by either hand and from various directions by personnel about the gun.

Additional objects, advantages and features of invention reside in the construction, arrangement and combination of parts involvedin the embodiment of the invention, as will be understood from the following description and accompanying drawings, wherein Fig. 1 is a fragmentary elevation partly in section of theleft side of a gun on which my invention is incorporated;

Fig. 2 is a fragmentary rear elevation partly in section of the breech ring and operating handle;

Fig. 3 is a section on the line 3-3 of Fig. 1, enlarged;

Fig. 4 is a fragmentary section on the line 4--4 of Fig. 2;

Fig. 5 is a section on the line 5-5 of Fig. 2.

The gun It! illustrated includes a well known form of breech closing and firing mechanism which is used without change of the principal elements. These are mountedas heretofore on a breech ring II into which the tube of the gun is fitted, the rear portion of the ring II being rectangular. The breech block I2 is shown, andv the semi-automatic breech mechanism and firing mechanism are omitted. The breech block is operated as heretofore well known, by a crank device (not shown) but corresponding to construction in patents named below, which is mounted on a spline shaft I3, a portion of which is shown at the left of the breech ring, in which it is mounted as heretofore. The shaft is rocked by an operating crank I4 on its right end, which is cammed by gun carriage parts (not shown) in recoil or counterrecoil of the piece as is known, as, for example, in the patent to Dearborn, 798,882; orDriggs, 1,393,353. Patent to Adelman et al., 1,359,454, also shows such constructions as above mentioned to lower the breech block, operate extractor devices, and place a closing spring I5 under tension tending to reverse the motion of the shaft; the conventional mechanism also including detent means (not shown) vto hold the block in open position against the reaction force of the closing spring until released by a cartridge shoved into the chamber of the gun such as in the patent to Driggs 1,393,353.

In the present instance a crank I 'I at the left on the spline shaft is utilized similar to one before located at the right side of the gun, to operate the closing spring chain I6 which has likewise been moved to the left side. The shaft is revoluble in transversely bored lugs I I projecting downwardly at the extreme lower forward part of the breech ring, and it projects at both sides of the ring. At the right it receives the operating crank I4, and at the left similarly holds the hub I8 of the chain terminal crank II, by which the spring I5 is placed under compression and through which the spring acts to close the breech when the block is released for such movement.

Heretofore, a breech vopening handle has been mounted on the shaft normally free on the shaft I3, and a manually operated clutch or connecting device was provided to be manipulated when the handle was to be used. This material has been dispensed with in the present instance and my improved construction substituted, which is always ready for normal operation without preliminary clutch manipulation, Vand still is inoperative and stationary during all other opening and closing operations of the breech block.

In the instant case, the breech. ring II is. recessed at I9 to receive the hub l'slidably and revolubly, the hub being splinedan'd freely-slidable on the end of the shaft I3 except when pinned as hereinafter referred to. The shaft also extends through the crank I'I, which rests-.close to the left planiform face of the breech ring, the shaft stopping flush with alower relieved-'outer face of the crank I'I.

The hub I8 is formed with a circumscribing round .bottomed -groove 201midway vof the depth of they recess I9,vand a pin 2| is inserted-'slidat'ly through the rear face of the lug I I' yofthe breech ringgthis pin being alinedl with and extending in a part of the groove as ay retainer for the hubarid chain crank II. Thispin may have a threaded screw head portion 22 engaging a corresponding threaded cuter bore portion in the ring IIy to' retain the pin, as in Figure 4.

The left endof the spline shaft' I3 (Fig. 2) is bored and counterboredto form a large outer socket 23, in which there is revolubly ftted the hub 24 of a breech-operating handle or lever'25, this hub and handle being boredand counter sunk to receive a, retaining and pintle screw 2S having a threaded tenon 2'I `engaged in the small inner bore of the spline shaft. The filister head 28 of the screw 26 sets in the counter-sink. in the handle 25. A diametrical bore is formed through the hubY I8, shaft I3, `and tenon 21,' in the plane of the-groove 20, and through .this boreand groove there is set a pin 29, which fixes these parts relatively and prevents looseningrof the screw 26. Withdrawal vf the chain-crank :and handle assembly is effected by removing. the pin 2 Land operating crank I4, and ywithdrawingthe shaft I3 to the left until the pin'29 is uncovered, rem-oval of the latter and the screw 26 leaving the: crank II and handle free for disassembly.

`The chain crank I'Iis thickenedat its-outer upper part at the left side, to forma cam30, terminating below at an abrupt planiform shoulder 3 I, which, when the crank is in closedbreech`-posi tion, is horizontal, with the cam body .and crank extending thereabove, as shown in Fig. 1. It extends a good distance forwardly of the vertical radius of the shaft I3. The form and radius of the crank I'I and cam 3 0 otherwise, the manner of connecting the chain thereto, and themounting of the latter and the' spring I5, conform to prior practice, and will not bedescribed, though illustrated.

The handle 25 is formed or provided with arcomplementary cam 32 thereon having a top,'plani form, forwardly located fat face 33, arranged flat against" the shoulder 3l, when the` lever is infits normal and initial position, Aand the crank I'I in its closedfbreech position, both shown in Fig. 1.

In this position of the handle, itfextends rear.- wardly and upwardly at an angle Iof approximately 45 degrees to the horizontal to a point near the rear or breech facerof thering II, wheretafrgrip portion 34 continues therefrom, `more nearlylperpendicular, in the. present instancefbeing .atfan angle of approximately fteendegrees to the perpendicular. Its extremity is at or near a level with the top of the breech ring I I, and also near or at the plane 0f the breech face.

The upper corner portions of the breech ring are bevelled as at 35 so that the extremity of the grip 34 lies above and rearwardly thereof. In this way, the'grip'does not project" into the paths of ordinaryy movements of personnel or'ammunition in the servicing of the gun, yet is immediately at the hand of the gunner or other of the gun squad,

forprompt operation when required. This is an important improvement, as, heretofore the handle was locatedata -lower and more forward position and could not be seen or reached readily from positions rearwardlyof or to the right of the breech.

TheI angular form of my handle lever does not impair its utility, but on the contrary, in its downiward movementdtfisfeasy to move, because it movesclear of the breech so that rapid movement is attainable with greater leverage advantage, by thezgreater lengthzprovided and.. also .because the weight ofrithel operator may be thrown thereon with greaterfacillty.

The fiat 33 is above andparallel to .a shoulder face '36.on thecam 32, tangent toa concentric surfacelvonf the rear: part of thexcam which will beclear Loffthe'shoulder 3| whenever the crank I1 rotates rearwardly from the `position shown in Fig. 1, thus avoiding friction with the handle. Withreferenceftothe handle, on thecontrary, anyrearward andl .downward movement thereof will cause the lat.=33zto engage the lforward part of theishoulzlerf3l `and cause the crank II to move ywith .the handle. This compresses the closingspring andv rotates thespline shaft, so that the vbreech block is movedA to open position where it will be'V Iheldbyithe extractors, as heretofore.

The handle lever 25: in the present instance is represented as a cast member, generally flat throughout, with its major medial plane parallel to the left sidezofv the breech ring. Owing to the thickness. of the crank I'Iand cams interposed between the handle and side of the ring II, the grip is spacedfrom the side of the ring II amply .'forthe-insertion 0f the hand of an operator in this space, so .that the handle maybe operated byeither the right or left hand.

In order to hold the handle 25 at normal initial inoperative position, a stop bracket 39 is bolted tothe side of the ring I I forwardly of thehandle, and located to receive the base Portion of the grip 34 vagainst -a lug 40 extendedto the left from thebracket. Th-ebracketconsists of .a block body having; a1 ia-tzsideI.` (lgsnzfandi) paralf lel to andclose-to-the planeof the handle movement, thisv side 4 I.ilying close beside the basefof the gripfilfl` when' the .latter is. in initiall forwardmost position. against the lug T46. The, rlatter is slightly recessed as ,at 42 so as vto receive partly therein the. forwardedge portion -ofl the'fhandle ,suiiieientlyl to. prevent lateral bendingof the handle yaway from the ring II. The recess providesa lip -42' lapping theforward partgof 'the handle shank4 only, projectingA rearwardly beside theV shank. fora part of its'major:cross sectional' dimension. The minor cross sectional dimension .of f' the lever 4is-fextremelyzsmall, `and lesszthan usuali in 4such. levers. :This is; important.v in enabling the usefoffless :material in the handle, while affording .adequate 'resistance to lateral shocks .and stresses.

Thev 'base .,ofxthegrip, A.beside the fiat side'Z 4iv -of the: fbracket," hasformed?A therethrough i anvaperturei 43; which-receives therein 'the outer end portion of a spring-pressed-detent,`latch,J or -plungg. erV seti a suitable socketY bore 39' vin the bracket 39. The socket bore is enlarged at its inner part to receive an enlarged integral sleeve part 44 of the detent, a coiled spring 45 being confined between the detent and the face of the ring I1. The bracket is fixed on the ring ll by screws 4l engaged through a foot flange 46 formed at the lower and forward sides only of the bracket 39.

A narrow longitudinal slot 48 is formed through the grip 34 in a plane at right angles to the left face of the ring Il and opening at its lower end into the outer or left part of the aperture 43. This slot extends longitudinally through the greater part of the length of the grip, and near its lowerr end a latch lever 49 is pivoted therein for movement in the slot on a pin U set across the slot in the medial major dimensional 'plane of the grip. The slot is extended further toward the extremity of the grip at the outer sid-e of the latter, than at the inner side, the underlying material at the inner side of the grip thus forming a stop 52, and the lat-ch lever 49 is similarly lengthened at its outer cr left edge, alording a tongue 5I to rest against the stop material 52 at the shorter part of the slot and check movement of the latch lever toward the inner side of the grip. The latch lever is shaped so as to lie within the left hand surface of the grip when checked against the stop 52 and at its inner side is enlarged so as to project from the grip a distance sufficient to be readily depressed by the ngers or palm of a hand in which the grip is grasped. The latch lever consists of a llat planiform plate which may be pressed entirely into the Vslot from the inner side of the grip. At its lower end the latch lever extends from its pivot pin 50 into the outer part of the aperture 43 with a size reduced suilciently for free movement from an initial position at the left toward the right. This extremity or arm 49' of the latch lever has an inturned finger 53 thereon, alined with the aperture 43 and resting against the outer end of the detent 44 normally. The latch lever is free in the slot 48 at all times and the movement of the finger 53 toward the right is limite'db'y a portion of material 54 of the handle, extending across the extreme lower part of the'slot 48 next to the finger 53, against which material the arm 49 engages so as to stop the nger ush with the innerside of the grip or at the plane of the surface' 4I. The plunger and its spring serve to hold the latch lever in initial positlon with the nger retracted to the left when the handle is in initial or inoperative position asin Figs. l, 2, and 3; and at the same time, the plunger, due to its engagement in the aperture 43, holds the handle in this position (which is its normal one), at which the plunger is engaged in the recess 42 in the lug 40. In order to give the detent plunger 44 a good bearing in the socket bore 39', its enlarged part 44 is extended longitudinally a distance less than the remaining depth of the bore to the face of the ring Il, and it is bored axially to form a sleeve receiving the left end of the spring 45.

The grip has a thickness substantially greater than the distance to which the plunger 44 engages therein, and at the forward edge of the grip a bevel surface 55 is formed on the inner side thereof, of such extent that, when the handle 25 is to the rear and is returned to initial position, the bevel will cam against the outer end of the plunger 44 and press the latter inward toward the right until the handle reaches its initial position, when the detent will move to the left into the aperture 43 by urging' of the spring 45,`

pressing the nger 53 outward, retracting the latch, and holding the handle in place in the re cess 42.

In the use of this invention, the handle is used ordinarily only to open the breech forthe rst round fired in an action; but in case of a misre, it is also required in order to open the breech and enable removal of the faulty round, or other correction of the fault causing misfunctioning.

When the breech is to be opened by my device, it may be done by a member of the gun squad at the left of the gun most conveniently, by extending the right hand forwardly between the breech ring Il and the grip 34 with fingers extended and the thumb disposed at the upperside of the hand; and when the mounts of the palm are adjacent the latch lever 49, pressing the hand to the left against the grip, depressing the latch and causing the nger 53 to press the plunger 44 clear of the grip; while at the same time the lingers of the soldier are bent around the grip and the handle pulled rearwardly, pressed downward through a full stroke movement, and released. Or, instead of being so released, the handle may be returned manually to its initial position at once. In the latter case, the breech block will remain in its opened position, which in the oase o-f the sliding block of the 75 mm. gun is a lowered position clear of the gun chamber, as shown. v

The latch lever may of course be moved to releasing position by the palm of the hand or the lingers or other Darts of the hand, and the handle may be operated very readily by the left hand as well as the right; left hand operation being most convenient for a gunner or squad member to the rear or at the right of the breech. In such operation, the ngers of the left hand, in grasping the grip 34 will extend therearound to its right side, and press against the latch lever, releasing the detent 44 thereby; at the same time that a rearward pull is applied to the handle to draw the latter rearward.

In the movement of the handle, the chain crank l1 will be drawn rearward by the upward and rearward pressure of the cam top face 33 against the cam shoulder 3| of the chain crank cam 30, the breech being opened at'the same time. The chain Y I'B thereby puts the breech closing spring I5 under compression so that its reaction through the chain and crank I1 may move the breech block l2 back to closed position when the handle 25 is free or in initial position and when the block is released by the detent for Ysuch movement. If the handle is not returned manually to its initial position after manual opening of the breech as described, but is left in its rearward lowered position, the first automatic closing of the breech when the block is released will move the handle back to its initial position by reverse action of the cam 30 against the cam 3'2, snapping the handle past the detent to the recess 42 'in the lug 40, where it will be held, as before indicated, and where it will remain throughout all subsequent semiautomatic operations of the breech mechanism. The cams 30 and 32 constitute a lost motion connection between the handle and spline shaft, and the normal operation of the breech and shaft is within the extent of the lost motion.

My invention is specially advantageous when smoke shells are employed with low propellant values, and the recoil produced is not suiicient to open the breech. Likewise. where subcaliber 7 practice is :carried Yout, with .-.eurrent equipment in which zthef standard breech mechanism 'func-r tions ,in .battery with thezsubcaliberl ammunition to close the breech and re the rounds, but the recoil-isainsucient to completely Qpenand lock the1bleck.

=Ihave :disclosed the. inventionin the. 'best construct-ion known to me, .but it`will ,nevertheless berunderstood that i this is purelyexemplarm` and that changes and modicationsiin :the conistruction, arrangement vand combination of parts otherwise Athan as specically claimed, andfrsubstitution of vmaterials and'l equivalents. mechanical or otherwise, may be made without departing from the `spirit ofthe inventionset'forth in lthe appended claims wherein-I claim:

ln YaV breech mechanism for lagunhaving a gun breech body, aY recoil-opened'breech closure, a transverse closure operating rock shaft vonsai'd bodyoperatively `onnected With said closure, a crank on said-rock shaft, -a closurespring means operatively conneotedto'said 4crankfsaid spring meansl being adapted to'be'tensionedby said s ha'ft upon rotationthereof in'onediretion to open said closure and being adapted to rotate said shaft in the reverse direction to close said-closure, said crank having a, shoulder projected Yaxially o'f -said shaft, a pintle on the end of said shaft adjacent saidv shoulder, an operating lever v'revolvablymountedonsaid pintle,'mean"s on said gun breech body for holding releasably sai'd'lever at an initial inoperative position, alu'g on said lever extending-into the path of said shoulder'whereby said-shaft can rotatein either of said ydirections independently of vsaid operating lever whenY the saine is held at saidinitial inoperative position and whereby said lug abuts said Yshoulder upon rotation `of said-'operating lever from said initial position'to rotate said shaft in a direction'to open the closure.

'-2. The structure of claim'l in fwhichsaid crank is 4beside the said body and hase vhub yslidably splined on the shaft'and inserted revolubly in the said body, said shoulder beingoiset longitudinally outward of the shaft, said shaftterminally bored y.ftdjacent said shoulder, said Ypintle being nXed coaxially in the Vshaft'and in said bore, Said'lever having@ hub'pert extended into Seid bore around the pintle, Said Dltlebeingheadd.

3, The 'structure of'claim' 1 in which said crank isbeside the saidfbodyand has a'hub slidably splined on the shaft and insertedmevolubly in the said body, said shoulder being Qffsetlongitudinally outward ,of the shaft, said 'shaft' terminallybored adjacent said shoulder, .said pintlebeing fixed coaxially in the shaftand in lsaid bore, said levenhaving .a hub .part ext/ended,into saidbore around .the pintle, said pintle being headed, said hub of .thelcrank being periphferalhr grooved, a

8 gentiallyto thefhub-"oisaidlcver andfslidahlv in. SadigfQQYef and a Diniellgarged throughsadjpll'. tle in the-plane of the groove andush atits ends with the .bottom ,of the latter.

4. A breech block operating lever Vand-detent therefor comprising -a gun-carried Amount .clOSe beside the path of the lever, avguide bore inthe mount normal to said'path andhavinga'reduced shoulder next to said path, said detentcomprisinga spring pressed plungerslidable in,;the:bore and having Va Vreduced part slidable past .said shoulder andi extended into. said path, saidIlever having an aperture arranged Ito aline 'withvr said extended partof the plunger atan initial inoperativ'e position of the lever, said lever v'having-"fa grip portion thereon 'longitudinally outwardof the aperture and having therethrough a slot alined with said aperture and 'plunger'at Asaid initial v position. of the `lever andfextending longi- 20. tud'inally in the grip, Va release lever 4p i'voted'in Number JName Date 14,1,868 .E1ward VA; A Aug'.1'9,` 18:13 13363120 Knowlton,--- l Q Fehia 1886 685,612 ,JaLkobsonT A 'O. ct. y29, vv19,01 5 785,085 Burton if?- Mar. .21, 19,05 896,659 schneider Aug. 1,81908 A1,966,814 Hermsdorf .J1i1y y,1913, 1,083,212 Dawson etai. ,Feb. 24, v19151 2,056,270 ,Harbert O ,ct.6v,. i936.v 2,216,860 summerben pct. .8, 1940 2,295,827 Breen etlal. Sept `15,119,112 2,328fli6 Fuehrer ,Allg. f3,1,. 1-943 FOREIGNTPATENTS o Number .Country pate ,676,633 Germany June 10, 1939v the s'lotadjacent the base of the grip amdhavingr an attenuated presser nger -extendedtoward said aperture for"depressin'g" engagement`V With and clearance of said plunger from saidpath on operative'movement of the-release leven-said 'rel lase'lever being'extended'to near the extremity of the grip andhaving a part eXten'dedlateraly from the grip'at initial position,saidp1ung`er bef ing'spring4 loaded to move the release leverv to said initial' position when said prt-asserpart is aiined and engaged therewith; 'yle'ldable tov 'm'anL ual pressurefa, car'nface on'the rst leverV ,arranged 'to wipe the'plllnger on return movement f the rstlever, means t'o limitsaidreturnmove'- ment, land means in vsaid slot to limit operative and return movements yof `the releaselever.

WILLIAM'SUMMERBFLL.-

REFERENCESCITED Thefollowing references are ofrecordinethe le of this patent:

UNITED STATES PATENTS 

